Envelope feed device incorporating scales

Abstract

The feed device includes a platform (9) adapted to receive at least one mail item (4; 4A, 4B) laid flat on it and a plurality of rollers (10) each having a flat (10B). Said rollers are mounted to rotate under the platform to occupy alternately a first position in which they remain below the platform and a second position in which they project above the platform. A weight sensor (30) is mounted under the platform to carry it, said sensor being responsive to vertical displacement of the platform to deliver a signal (C) indicative of the load applied to it when the rollers are all substantially in said first position.

We claim: 
     
       1. A device for feeding mail items to a franking machine, including a platform adapted to receive at least one mail item laid flat on said platform and a plurality of rollers, said rollers each having a flat portion and being mounted to rotate under the platform to occupy alternately a first position in which said rollers remain below the platform and a second position in which said rollers project above the platform, said device comprising at least one weight sensor mounted under the platform, said sensor being responsive to vertical displacement of the platform to deliver a signal indicative of a load applied to the platform when the rollers are all substantially in said first position. 
     
     
       2. A device according to claim 1, wherein four of said weight sensors are disposed under the platform which has a rectangular surface under each corner of which is one of the weight sensors. 
     
     
       3. A device according to claim 1, wherein each sensor is protected against overloading of the platform by an abutment disposed under the platform. 
     
     
       4. Feed device according to claim 1, wherein each weight sensor (30) is a strain gauge. 
     
     
       5. A device for feeding mail items to a franking machine, comprising: a platform adapted to receive at least one mail item laid flat on said platform and a plurality of rollers, said rollers each having a flat portion and being mounted to rotate under the platform to occupy alternately a first position in which said rollers remain below the platform and a second position in which said rollers project above the platform;   at least one weight sensor mounted under the platform, said sensor being responsive to vertical displacement of the platform to deliver a signal indicative of a load applied to the platform when the rollers are all substantially in said first position; and   control means connected to the weight sensor for commanding either rotation of the rollers to move said mail item on the platform to one end of the platform or halting of rotation of the rollers so that said rollers occupy said first position in order to begin a phase of weighing said mail item resting on the platform.   
     
     
       6. A device according to claim 5, wherein the control means command halting of rotation of the rollers in response to a signal supplied by a photo-electric cell cooperating with a ring rotationally coupled to the rollers. 
     
     
       7. A device according to claim 6, wherein the control means are adapted to operate in the following manner when a stack of mail items is resting on the platform: a) to determine the mass of the stack of mail items resting on the platform in response to the signal supplied by each sensor if the rollers occupy the first position;   b) to command rotation of the rollers to separate a first mail item from the stack of mail items;   c) to command halting of rotation of the rollers when the rollers occupy the first position and said first mail item has been extracted from the stack;   d) to determine the mass of the stack of mail items resting on the platform in response to the signal supplied by each sensor;   e) to calculate the mass of said first item on the basis of the difference between the mass determined in step a) and the mass determined in step d).   
     
     
       8. A modular franking machine including a feed device for feeding mail items to a franking machine, said feed device comprising a platform adapted to receive at least one mail item laid flat on said platform and a plurality of rollers, said rollers each having a flat portion and being mounted to rotate under the platform to occupy alternately a first position in which said rollers remain below the platform and a second position in which said rollers project above the platform, said device comprising at least one weight sensor mounted under the platform, said sensor being responsive to vertical displacement of the platform to deliver a signal indicative of a load applied to the platform when the rollers are all substantially in said first position; and   a franking module connected to interwork with the feed device so that the feed device feeds the franking module with mail items and simultaneously supplies the franking module with data indicative of the mass of the mail items or a franking amount of the mail items.